1. Field of the Invention
The invention relates to a curtain airbag system.
2. Description of Related Art
A curtain airbag system is known which includes a main inflatable portion provided at a seating location at which an occupant is seated, and an auxiliary inflatable portion that is constantly in fluid communication with the main inflatable portion via a reduced-diameter portion and is located off the occupant seating location (see, for example, Japanese Patent Application Publication No. 2007-161163 (JP 2007-161163 A)). It is also known to provide a curtain airbag with a second deployment portion that extends below the belt line, at a location other than the occupant seating location (see, for example, Japanese Patent Application Publication No. 2007-161167 (JP 2007-161167 A)).
As one example of measures to ensure sufficient reaction force when the curtain airbag protects an occupant against rollover of the vehicle, the thickness of the curtain airbag is increased. In this case, the volume of the curtain airbag, or the capacity of the inflator, is increased.